This proposal to the NCRR Shared Instrumentation Grant Program requests funds to acquire an automated DNA sequencing machine and data storage equipment for shared use by NIH-funded investigators at the Marine Biological Laboratory. The equipment to be purchased includes an Applied Biosystems 3730XL DNA Analyzer and a 3.4 tera-byte data storage system based upon Apple Computer's Xserve RAID and Xserve G5 architecture. The equipment will accommodate new DNA sequencing requirements for five new NIH programs (funded within the last year or projects to be activated by May 1, 2004). These NIH projects include several Serial Analysis of Gene Expression (SAGE) studies in parasitic protists, a large-scale evolutionary analysis of cDNAs from as many as thirty parasitic protists, sequence and Serial Analysis of Ribosomal Sequence Tags (SARST) analyses of environmental PCR amplicons for the new Woods Hole Center for Oceans and Human Health (COHH) program, and small-scale genome studies of symbiotic prokaryotes. These projects will impact our understanding of patterns of gene expression in human pathogens, the evolution of protists that cause disease, the dispersal of pathogenic microrganisms in marine environments, and adaptive mechanisms that lead to parasitic lifestyles. This equipment will nearly double our current sequencing capacity, which is currently fully subscribed. The equipment will operate within the W.M. Keck Ecological and Evolutionary Genetics Facility within the Bay Paul Center at the Marine Biological Laboratory. The facility is a shared-use resource for investigators in the Woods Hole Scientific Community and is equipped with robotic systems for colony picking, template production, preparation of sequencing reactions, automated DNA sequencing and DNA microarraying. Since 1997, a users' committee has guided use of the facility, which is managed by a faculty member in the Bay Paul Center. Foundation funds have been reserved to pay for five years of maintenance. [unreadable] [unreadable]